Relative humidity is the percentage of water vapor that is i

Theoretical perfect combustion in a diesel engine yields by-products of_____.

A.aldehydes and carbon dioxide

B.water vapor and carbon monoxide

C.nitrogen and carbon monoxide

D.water vapor and carbon dioxide

The expression THE AIR IS SATURATED means ______.

A.the relative humidity is 100%

B.the vapor pressure is at its minimum for the prevailing temperature

C.precipitation has commenced

D.cloud cover is 100%

critical relative humidity

As the temperature for an air mass decreases, the ______.

A.absolute humidity increases

B.relative humidity increases

C.specific humidity increases

D.dew point rises

Haze is not caused by ______．

A.forest fires

B.smoke from industrial areas

C.dust or sand storms

D.water droplets with the relative humidity more than 95%

The effective temperature of air is dependent upon ______. I. relative humidity II. air velocity

A.I only

B.II only

C.Both I and II

D.Neither I nor II

The dew point is reached when the ______.

A.temperature of the air equals the temperature of the seawater

B.atmospheric pressure is 14.7 lbs. per square inch

C.relative humidity reaches 50%

D.air becomes saturated with water vapor

A.cooling only

B.cooling and humidifying

C.cooling and dehumidifying

D.adiabatic(绝热的)cooling

A hygrometer is device used for determining ______.

A.the absolute temperature

B.atmospheric pressure

C.wind velocity

D.relative humidity

As the temperature for a given mass of air increases, the ______.

A.dew point increases

B.dew point decreases

C.relative humidity increases

D.relative humidity decreases